MatterMatter• It must have mass (weight)• It must have volume (occupy space)

Rocks Sunlight Gravity

Basic ChemistryBasic Chemistry• Atom: Smallest part of an

element. Can’t be broken down any further (maybe!).

• Nucleus - has protons (+ve) and neutrons (no charge)

• Orbitals - have electrons (-ve)

• # of protons = # of electrons. This makes the atom have no net charge (atom is neutral)

• Atomic Number = # of protons Ex. Atomic Number of Fe (Iron) is 26•Atomic Weight= # of protons + # of neutrons Ex: Atomic Weight of Fe (iron) is 26 + 30 = 56•Can you calculate number of neutrons if Atomic Weight and Atomic Number is known?•# of Neutrons = Atomic Weight- Atomic Number

Atomic Weight

Atomic Number

• Element is Carbon• Atomic Number = 6• This means number of protons = 6• Also, number of electrons = 6• Mass Number = 12 = (Atomic Weight)• Number of Neutrons = 12 - 6 = 6

6C12

• Element: substance composed of one kind of atom & can not be broken down by normal chemical means.

• Ion: an atom that has gained or lost electrons, giving it a positive or negative charge.

Gold Ion has lost an Electron

Salt is Sodium ChlorideSalt is Sodium ChlorideSodium (Na) atom Chlorine (Cl) atom

SALT is NaCl

Note: NaCl is a compound - has 2 elements

• Isotope: a form of atom having the same atomic number but a different atomic weight

Example

6C126C14

Radioactive Isotope

Number of Neutrons will be different in ISOTOPES!

CHOPKINS CaFe Mg NaClCHOPKINS CaFe Mg NaClChopkins café (has) mighty good SaltChopkins café (has) mighty good Salt

• C = Carbon• H = Hydrogen• O = Oxygen• P = Phosphorus• K = Potassium• I = Iodine

• N = Nitrogen • S = Sulfur• Ca = Calcium• Fe = Iron• Mg = Magnesium• Na = Sodium• Cl = Chlorine

Molecules and compoundsMolecules and compounds• A compound

– Combination of two or more elements– Combined “chemically”– Has definite proportions

• A molecule– Smallest part of most compounds– Hard to break up into element that

make it O2

C6H12O6

Molecules and compoundsMolecules and compounds

H2

C55H72O5N4Mg

NH3

C6H12O6

H2O

Hydrogen Gas

Chlorophyll A

Ammonia

Glucose Sugar

Water

• Match the following: